Infinite work is less work

Re:Infinite work is less work by evandijk70 on Thursday July 11, 2019 @08:28AM (#20410975)

I am not familiar with Perl 6, nor with list comprehensions, but I am wondering if this is really more readable than the 'traditional' way of looping through the prime numbers and appending to the list, like this:

  strongs=[]
  weaks=[]

  n=1
  AskedNumbers=10
  while len(strongs) < AskedNumbers:
    if p(n) * 2 > ( p(n-1) + p(n+1) ):
       if len(strongs) < AskedNumbers:
         strongs.append(p(n))
    if p(n) * 2 < ( p(n-1) + p(n+1)):
       if len(weaks) < AskedNumbers:
         weaks.append(p(n))
    n+=1
  print(strongs)
  print(weaks)

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Re:Infinite work is less work by eequah9L on Thursday July 11, 2019 @10:20AM (#20411677)

I am not familiar with Perl at all, though I am with list comprehensions, and FWIW I find the code very readable. (Though the lambda syntax was not obvious at first.)

What I would worry about is performance. But we are talking about top ten numbers, so whatever. (If it does actually matter, just precompute the lists.) But for larger sets I would check how is-prime is actually implemented :)

[EDIT: Grammar.]

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Re:Infinite work is less work by hawkice on Thursday July 11, 2019 @10:29AM (#20411753)

That does lots of redundant prime checks, and presumed strong primes are rarer than weak primes, which is _implied_ in the article, but reading your code, nobody would know that (I'm not even sure I know it, really).

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